The present invention relates to a wire winding system and more particularly to a dancer assembly for use in a wire winding system for controlling the tension of the wire traveling from a point of manufacture to a take up reel.
In a wire winding system used in the manufacture of insulated wire, the wire is ordinarily advanced continuously by a capstan assembly from an extruder or enameler to a take-up mechanism. The capstan assembly operates at a substantially constant linear speed to draw the wire at substantially constant speed. The tension in the wire is substantially constant. The take-up mechanism includes one or more reels driven at variable speeds to compensate for the varying speeds necessary to take up wire on a reel of changing effective diameter and weight.
The wire passing from the capstan assembly to the take-up mechanism usually passes over a dancer unit, which is movable with variations in the take up speed of the wire to help compensate for the tension differences caused in the wire by the varying take-up speed. At higher operating speeds, on the order of 600-1100 feet per minute, substantial tension is imparted to the wire and it is imperative that the dancer unit operate quickly to prevent breaking of the wire, which could cause shut down of the wire winding system. The result would be manufacturing delays and waste of material.
Various means have been employed to control the tension of the wire in such wire winding system. In one known arrangement wire travels about a dancer weight unit where numerous loops are formed in the wire causing the weighted roller of the unit to move up and down with variations in the take up speed of the wire. See, for example, Wahl 3,038,674, Ludwig 3,169,715, and Tarulli 3,994,445. The wire undesirably passes over a plurality of pulleys and is work hardened. This is unwanted in many applications, for example, winding magnet wire. Another arrangement for controlling wire tension includes an air cylinder, which employs air pressure in opposition to the force of the wire against a pulley in the dancer unit. The air cylinder arrangement is somewhat complex and has been subject on occasion to leaks or loss of air pressure. It has been found difficult to control with reliability, particularly when very fine gauge wire is used. Another arrangement for controlling the wire tension involves applying weight to the dancer pulley in opposition to the force of the wire. A different weight is required for each gauge of wire. A plurality of separate weights are required and keeping tracking of the various loose weights has been a problem.
An object of the present invention is to provide an improved tension control arrangement for a wire winding system wherein the disadvantages and deficiencies of prior construction are obviated.
Another object of the present invention is to provide an improved tension control system for a wire winding system for handling selectively one of a plurality of wire gauges, which control system includes a dancer unit with a single pulley, variable weight means for applying weight to the dancer unit, and wire gauge selection means for positioning the variable weight means to apply a predetermined weight to the wire corresponding to a selected wire gauge.
Yet another object of the present invention is to provide an improved tension control system for a wire winding system including a dancer unit, a chain with a plurality of weights permanently affixed thereto, the weights calibrated to predetermined wire gauges, and calibration means operably connected to the chain to apply a predetermined weight to the dancer unit, said calibration means including a calibration knob having indicia thereon corresponding to the desired wire gauges to be run, and said calibration knob being rotatable to an index position corresponding to one of said indicia to apply a corresponding predetermined weight to said dancer unit.
Other objects and advantages of the present invention will be made more apparent hereinafter.